//
// Created by Pulsar on 2020/5/18.
//

#include <rc_cv/MatConvert.h>
#include <opencv2/imgcodecs/legacy/constants_c.h>
using namespace cv;
std::string base64Decode(const char *Data, int DataByte) {
    //解码表
    const char DecodeTable[] =
            {
                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                    62, // '+'
                    0, 0, 0,
                    63, // '/'
                    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
                    0, 0, 0, 0, 0, 0, 0,
                    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
                    13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
                    0, 0, 0, 0, 0, 0,
                    26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
                    39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
            };
    std::string strDecode;
    int nValue;
    int i = 0;
    while (i < DataByte) {
        if (*Data != '\r' && *Data != '\n') {
            nValue = DecodeTable[*Data++] << 18;
            nValue += DecodeTable[*Data++] << 12;
            strDecode += (nValue & 0x00FF0000) >> 16;
            if (*Data != '=') {
                nValue += DecodeTable[*Data++] << 6;
                strDecode += (nValue & 0x0000FF00) >> 8;
                if (*Data != '=') {
                    nValue += DecodeTable[*Data++];
                    strDecode += nValue & 0x000000FF;
                }
            }
            i += 4;
        } else {
            Data++;
            i++;
        }
    }
    return strDecode;
}


std::string base64Encode(const unsigned char *Data, int DataByte) {
    //编码表
    const char EncodeTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    //返回值
    std::string strEncode;
    unsigned char Tmp[4] = {0};
    int LineLength = 0;
    for (int i = 0; i < (int) (DataByte / 3); i++) {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        Tmp[3] = *Data++;
        strEncode += EncodeTable[Tmp[1] >> 2];
        strEncode += EncodeTable[((Tmp[1] << 4) | (Tmp[2] >> 4)) & 0x3F];
        strEncode += EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
        strEncode += EncodeTable[Tmp[3] & 0x3F];
        if (LineLength += 4, LineLength == 76) {
            strEncode += "\r\n";
            LineLength = 0;
        }
    }
    //对剩余数据进行编码
    int Mod = DataByte % 3;
    if (Mod == 1) {
        Tmp[1] = *Data++;
        strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode += EncodeTable[((Tmp[1] & 0x03) << 4)];
        strEncode += "==";
    } else if (Mod == 2) {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode += EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
        strEncode += EncodeTable[((Tmp[2] & 0x0F) << 2)];
        strEncode += "=";
    }


    return strEncode;
}

//imgType 包括png bmp jpg jpeg等opencv能够进行编码解码的文件
std::string Mat2Base64(const cv::Mat &img, std::string imgType) {
    //Mat转base64
    std::string img_data;
    std::vector <uchar> vecImg;
    std::vector<int> vecCompression_params;
    vecCompression_params.push_back(95);
    vecCompression_params.push_back(90);
    imgType = "." + imgType;
    cv::imencode(imgType, img, vecImg, vecCompression_params);
    img_data = base64Encode(vecImg.data(), vecImg.size());
    return img_data;
}


cv::Mat Base2Mat(std::string &base64_data) {
    cv::Mat img;
    std::string s_mat;
    s_mat = base64Decode(base64_data.data(), base64_data.size());
    std::vector<char> base64_img(s_mat.begin(), s_mat.end());
    img = cv::imdecode(base64_img, CV_LOAD_IMAGE_COLOR);
    return img;
}